What is the management of meningoencephalitis?

Management of Meningoencephalitis

The management of meningoencephalitis requires immediate empiric antimicrobial therapy, aggressive control of elevated intracranial pressure through CSF drainage, and supportive critical care measures, with the specific antimicrobial regimen determined by the underlying etiology (bacterial, viral, or fungal). 1

Immediate Initial Management

Antimicrobial Therapy

• Blood cultures must be obtained immediately, followed by empiric antimicrobial therapy without delay, even before lumbar puncture if imaging or lumbar puncture will be delayed. 1
• For bacterial meningitis, ceftriaxone 2 grams IV every 12-24 hours is the cornerstone of empiric therapy, with dosing up to 4 grams daily for confirmed meningitis. 2
• In meningitis cases, ceftriaxone should be administered at 100 mg/kg/day (not exceeding 4 grams daily) as the initial therapeutic dose, continued for 7-14 days typically. 2
• Delay in antimicrobial initiation significantly increases morbidity and mortality. 1

Diagnostic Lumbar Puncture Timing

• Perform lumbar puncture immediately to measure opening pressure and obtain CSF for analysis. 1
• Delay lumbar puncture only if focal neurologic signs, impaired mentation, or papilledema are present—obtain CT or MRI first to rule out mass lesions or obstructive hydrocephalus that increase herniation risk. 1
• If imaging or lumbar puncture must be delayed, administer antimicrobials first based on blood cultures alone. 1

Management of Elevated Intracranial Pressure

Baseline Assessment and Monitoring

• Measure opening pressure at baseline lumbar puncture—this is critical as elevated ICP (≥25 cm CSF) is present in approximately 50% of patients and correlates with early mortality. 1
• Patients who died within the first 2 weeks of therapy had baseline ICP ≥25 cm CSF in 11 of 12 cases. 1
• Failure to measure and manage elevated CSF pressure results in new neurologic abnormalities in 50% of patients versus 8% when guidelines are followed. 1

CSF Drainage Protocol

• If CSF pressure is ≥25 cm CSF with symptoms of increased ICP, perform therapeutic lumbar puncture to reduce opening pressure by 50% if extremely high, or to normal pressure of ≤20 cm CSF. 1
• For persistent pressure elevation ≥25 cm CSF with symptoms, repeat lumbar puncture daily until CSF pressure and symptoms stabilize for >2 days. 1
• CSF drainage provides immediate relief of severe headaches and improved sense of well-being, while persistently elevated pressure correlates with clinical failure. 1

Advanced ICP Management

• Consider temporary percutaneous lumbar drains for patients requiring repeated daily lumbar punctures—these can be safely maintained for up to 13 days with bacterial superinfection risk <5%. 1
• Ventriculostomy should be considered for patients with obstructive hydrocephalus or when lumbar puncture is contraindicated. 1
• Permanent ventriculoperitoneal shunts should only be placed after appropriate antifungal therapy has been initiated and more conservative measures have failed, but can be placed during active infection if clinically necessary. 1
• In one series of 27 patients with obstructive hydrocephalus, 63% had good outcomes following permanent shunt placement, though outcomes were worse with Glasgow Coma Score <9, suggesting early placement benefits severe cases. 1

Medications to AVOID for ICP Management

• Do NOT use acetazolamide—a randomized trial was stopped prematurely due to severe metabolic acidosis and complications. 1
• Do NOT use high-dose corticosteroids for ICP elevation—mortality and clinical deterioration were observed more commonly in corticosteroid recipients. 1
• Medications other than antifungal drugs are not useful for managing increased ICP in cryptococcal meningoencephalitis. 1

Supportive Critical Care Management

Hemodynamic Management

• Maintain euvolemia with crystalloids as initial fluid of choice to achieve normal hemodynamic parameters and mean arterial pressure ≥65 mmHg. 1
• Avoid fluid restriction attempting to reduce cerebral edema—this is not recommended. 1
• Use norepinephrine as the initial vasopressor for hypotension after euvolemia is restored. 1
• Consider albumin for persistent hypotensive shock despite corrective measures. 1
• Consider hydrocortisone 200 mg daily for persisting hypotensive shock. 1

Seizure Management

• Treat suspected or proven seizures early—seizures occur in 15% of bacterial meningitis patients and are associated with worse outcomes. 1
• Patients with suspected status epilepticus (including non-convulsive status) with fluctuating GCS off sedation or subtle abnormal movements require EEG monitoring. 1

General ICP Control Measures

• Maintain head elevation, normal to elevated MAP, control venous pressure, avoid hyperthermia and hyponatraemia, and maintain normocarbia and normoglycemia. 1
• Routine ICP monitoring is not recommended for all patients. 1

Etiology-Specific Considerations

Cryptococcal Meningoencephalitis

• Primary therapy: Amphotericin B deoxycholate (0.7-1.0 mg/kg/day IV) plus flucytosine (100 mg/kg/day orally in 4 divided doses) for at least 2 weeks, followed by fluconazole (400 mg daily) for minimum 8 weeks. 1
• Lipid formulations of amphotericin B (liposomal AmB 3-4 mg/kg/day IV or ABLC 5 mg/kg/day IV) can substitute for patients with or predisposed to renal dysfunction. 1
• The 2-week CSF culture result is critical for determining fungicidal success—negative cultures should be the goal, and patients not achieving this need prolonged induction therapy. 1

Bacterial Meningitis

• Ceftriaxone penetrates inflamed meninges effectively, achieving CSF concentrations of 5.6-6.4 mcg/mL in pediatric meningitis patients. 2
• Continue therapy for at least 2 days after signs and symptoms resolve, with usual duration 4-14 days; for Streptococcus pyogenes, continue at least 10 days. 2

Surgical Decompression for Refractory Cases

• When maximal medical ICP treatment fails to reduce severe intracranial hypertension, decompressive craniectomy should be rapidly proposed. 3
• Decompressive hemicraniectomy or bifrontal craniectomy has been reported as life-saving in medically refractory intracranial hypertension from meningoencephalitis. 4
• Early surgical intervention may enhance benefits, with immediate ICP reduction achieved in most cases. 4

Prognostic Factors

• Mortality rates for severe meningoencephalitis requiring ICU care range from 11-25%, with functional disability in 15-25% of survivors. 5
• Poor outcome predictors include: older age, immunocompromised status, focal neurologic signs, abnormal brain imaging, and delayed antimicrobial administration. 5
• Recent multicenter studies demonstrate that aggressive ICP management and early antimicrobial therapy are the most modifiable factors affecting survival. 5, 6